Automatic sandpaper replacement device for cnc production line

ABSTRACT

The present invention discloses an automatic sandpaper replacement device for CNC production line, comprising an automatic sandpaper supply mechanism which comprises a bracket assembly, and a sandpaper receiving assembly and a sandpaper extracting plate disposed on bracket assembly; and an automatic sandpaper peeling mechanism that is mated with bracket assembly, and comprises a mounting plate, and a peeling drive assembly and a peeling assembly mounted on mounting plate; wherein peeling assembly is drivingly connected with peeling drive assembly, peeling assembly periodically peels off waste sandpaper on a sanding head under driving of peeling drive assembly, and sandpaper extracting plate periodically supplies new sandpaper to sanding head after peeling off sandpaper. The automatic sandpaper replacement device improves peeling efficiency, effectively solves problems of uncleanly peeling and peeling residue, saves cost, solves sandpaper jamming problem in a sandpaper supply process, and improves sandpaper replacement efficiency and success rate, thereby further improving productivity.

TECHNICAL FIELD

The present invention relates to the field of CNC production lines, and more particularly to an automatic sandpaper replacement device for CNC production line.

BACKGROUND

A CNC sanding machine tool is usually provided in the CNC production line to polish and sand resulting machined parts or structural parts to meet designed surface finish requirements. For an existing CNC sanding machine tool, peeling and replacement of sandpaper is relatively cumbersome and has low degree of automation, which requires many manual steps and has the following disadvantages: low peeling and replacement efficiency of sandpaper, being prone to peeling off uncleanly, peeling residues, low replacement efficiency of sandpaper, and frequent downtime problem of a supply device caused by sandpaper jamming. In view of this, it is necessary to develop an automatic sandpaper peeling mechanism for CNC production line to solve the above problems.

DESCRIPTION

In view of the deficiencies in the prior art, it is an object of the present invention to provide an automatic sandpaper replacement device for CNC production line, which can improve peeling efficiency, effectively solve problems of uncleanly peeling and peeling residue, save cost, solve sandpaper jamming problem in a sandpaper supply process, and improve sandpaper replacement efficiency and success rate, thereby further improving productivity.

To achieve the above mentioned object and other advantages of the present invention, there is provided an automatic sandpaper replacement device for CNC production line, comprising:

an automatic sandpaper supply mechanism, the automatic sandpaper supply mechanism comprising a bracket assembly, and a sandpaper receiving assembly and a sandpaper extracting plate disposed on the bracket assembly; and

an automatic sandpaper peeling mechanism that is mated with the bracket assembly, the automatic sandpaper peeling mechanism comprising a mounting plate, and a peeling drive assembly and a peeling assembly mounted on the mounting plate;

wherein the peeling assembly is drivingly connected with the peeling drive assembly, the peeling assembly periodically peels off waste sandpaper on a sanding head under driving of the peeling drive assembly, and the sandpaper extracting plate periodically supplies new sandpaper to the sanding head after peeling off sandpaper.

Preferably, the bracket assembly comprises a base plate and a sandpaper extracting driving part, and the sandpaper receiving assembly and the sandpaper extracting plate are disposed on the base plate.

Preferably, the sandpaper receiving assembly comprises a sandpaper receiving canister and a sandpaper pressing block, the sandpaper extracting plate is slidably connected to the base plate, and the sandpaper receiving canister is provided with a first through hole running through the upper and lower ends of the sandpaper receiving canister so that the upper end and the lower end of the sandpaper receiving canister are both open.

Preferably, the bottom of the sandpaper receiving canister is provided with a second through hole running through the left and right sides of the sandpaper receiving canister so that the bottom of the sandpaper receiving canister is provided with a left through opening and a right through opening, the sandpaper pressing block is slidably disposed in the first through hole, the sandpaper extracting plate is passed through the second through hole, and the sandpaper extracting plate can be reciprocally slide along the base plate under the driving of the sandpaper extracting driving part.

Preferably, the mounting plate is mated with the bracket assembly and extends in a vertical direction, and the peeling assembly comprises a peeling mounting plate and a peeling plate fixedly mounted on the peeling mounting plate, wherein the peeling mounting plate extends in a vertical direction, the peeling mounting plate is drivingly connected to the peeling drive assembly, and the peeling plate can be reciprocated in a vertical plane with the peeling mounting plate under driving of the peeling drive assembly.

Preferably, a fitting plate is fixedly mounted on the peeling mounting plate, and the fitting plate is located directly below the peeling plate.

Preferably, the peeling plate and the fitting plate are located in the same vertical plane and are spaced apart to form a sandpaper collecting space between them.

Preferably, a lower edge of the peeling plate is provided with a peeling guide slope extending obliquely upward along the inner side of the peeling plate, and an angle θ between the peeling guide slope and the vertical plane is as follows:

3°≤θ≤8°.

Preferably, a sandpaper guiding structure having a mountain-shaped cross section is integrally formed at an upper edge of the fitting plate, and the sandpaper guiding structure comprises:

a first guiding slope extending obliquely upward on the outer side of the fitting plate, the first guiding slope being inclined to the inner side of the fitting plate; and

a second guiding slope extending obliquely upward on the inner side of the fitting plate, the second guiding slope being inclined to the outer side of the fitting plate,

wherein an angle α between the first guiding slope and the vertical plane and an angle β between the second guiding slope and the vertical plane are as follows:

15°≤α≤30°, 5°≤β≤15°.

Preferably, a sandpaper extracting groove is disposed on an upper surface of the sandpaper extracting plate, the sandpaper extracting groove is located at one end of the sandpaper extracting plate, and the sandpaper extracting groove is selectively mated with the first through hole in the process of reciprocally sliding of the sandpaper extracting plate along the base plate.

The present invention comprises at least the following beneficial effects compared to the prior art:

1. Since the peeling assembly is drivingly connected with the peeling drive assembly, the peeling assembly periodically peels off waste sandpaper on the sanding head under driving of the peeling drive assembly, and the sandpaper extracting plate periodically supplies the new sandpaper to the sanding head after peeling off the sandpaper, so that peeling and replacement of the sandpaper can be completed in a single operation, thereby omitting intermediate steps, improving peeling and replacement efficiency of the sandpaper, and further improving production efficiency. 2. Since the sandpaper pressing block is slidably disposed in the first through hole, the sandpaper extracting plate is passed through the second through hole, and the sandpaper extracting plate can be reciprocally slide along the base plate under driving of the sandpaper extracting driving part, the sandpaper extracting plate can periodically take out the sandpaper from the sandpaper receiving canister. 3. Since the upper surface of the sandpaper extracting plate is provided with a sandpaper extracting groove and the sandpaper extracting groove is selectively mated with the first through hole, the sandpaper can periodically fall into the sandpaper extracting groove and can be moved with the sandpaper extracting groove to an sandpaper attaching workstation. 4. Since the peeling mounting plate can be reciprocated in a vertical plane under driving of the peeling drive assembly, the peeling plate can periodically peel off waste and damaged sandpaper from the sanding head. 5. Since much of the sandpaper may be warped and damaged after sanding and the fitting plate can apply a certain pressure to the sanding head, the sandpaper on the sanding head is pressed and flattened so that the peeling plate can easily and quickly invade the sandpaper layer, thereby improving success rate for peeling off the sandpaper. 6. Since the lower edge of the peeling plate is provided with a peeling guide slope extending obliquely upward along the inner side of the peeling plate, the peeling guide slope enables a peeled off waste sandpaper to be directed obliquely upward into a sandpaper drop channel between the peeling mounting plate and the mounting plate, thereby increasing discharge efficiency of the waste sandpaper. 7. On the one hand, the sandpaper guiding structure can prevent the peeling plate from being difficult to invade due to the over-tightening of the upper edge of the sandpaper by the fitting plate. And on the other hand, the sandpaper guiding structure can prevent the waste sandpaper debris from remaining on the top of the fitting plate, thereby facilitating the effective discharge of the waste sandpaper.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a stereogram of automatic sandpaper replacement device for CNC production line according to the present invention.

FIG. 2 is a stereogram of an automatic sandpaper supply mechanism in automatic sandpaper replacement device for CNC production line according to the present invention, the automatic sandpaper supply mechanism being in a state of sandpaper attachment.

FIG. 3 is an inner structural stereogram of an automatic sandpaper supply mechanism in automatic sandpaper replacement device for CNC production line according to the present invention, the automatic sandpaper supply mechanism being in a state of sandpaper attachment.

FIG. 4 is a front view of an automatic sandpaper supply mechanism in automatic sandpaper replacement device for CNC production line according to the present invention, the automatic sandpaper supply mechanism being in a state of sandpaper attachment.

FIG. 5 is a top view of an automatic sandpaper supply mechanism in automatic sandpaper replacement device for CNC production line according to the present invention, the automatic sandpaper supply mechanism being in a state of sandpaper attachment.

FIG. 6 is a cross-sectional view along the A-A direction in FIG. 5.

FIG. 7 is an inner structural stereogram of an automatic sandpaper supply mechanism in automatic sandpaper replacement device for CNC production line according to the present invention, the automatic sandpaper supply mechanism being in a state of sandpaper extracting.

FIG. 8 is a top view of an automatic sandpaper supply mechanism in automatic sandpaper replacement device for CNC production line according to the present invention, the automatic sandpaper supply mechanism being in a state of sandpaper extracting.

FIG. 9 is a cross-sectional view along the B-B direction in FIG. 8.

FIG. 10 is an exploded view of an automatic sandpaper supply mechanism in automatic sandpaper replacement device for CNC production line according to the present invention, the automatic sandpaper supply mechanism being in a state of sandpaper attachment.

FIG. 11 is a stereogram of an automatic sandpaper peeling mechanism in automatic sandpaper replacement device for CNC production line according to the present invention. At this time, the peeling plate on the automatic sandpaper peeling mechanism is at the highest point and is in a state to perform peeling off.

FIG. 12 is a stereogram of cooperation between an automatic sandpaper peeling mechanism and a sanding head in automatic sandpaper replacement device for CNC production line according to the present invention. At this time, the peeling plate on the automatic sandpaper peeling mechanism is at the highest point and is in a state to perform peeling off.

FIG. 13 is a front view of cooperation between an automatic sandpaper peeling mechanism and a sanding head in automatic sandpaper replacement device for CNC production line according to the present invention. At this time, the peeling plate on the automatic sandpaper peeling mechanism is at the highest point and is in a state to perform peeling off.

FIG. 14 is a cross-sectional view along the C-C direction in FIG. 13.

FIG. 15 is a stereogram of cooperation between an automatic sandpaper peeling mechanism and a sanding head in automatic sandpaper replacement device for CNC production line according to the present invention. At this time, the peeling plate on the automatic sandpaper peeling mechanism is at the lowest point and is in a peeling off state.

FIG. 16 is a stereogram of a cushion of a sanding head in automatic sandpaper replacement device for CNC production line according to the present invention.

DETAILED DESCRIPTION

The present invention will be described in further detail with reference to the accompanying drawings below. The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent, in order to enable person skilled in the art to practice with reference to the description. In the Figures, shapes and dimensions can be enlarged for clarity, and the same reference numerals will be used in all drawings to refer to the same or similar components. In the following description, terms such as center, thickness, height, length, front, back, rear, left, right, top, bottom, upper, lower, etc. are based on the orientation or positional relationship shown in the drawings. In particular, “height” corresponds to the size from top to bottom, “width” corresponds to the size from left to right, and “depth” corresponds to the size from front to back. These relative terms are for convenience of description and are generally not intended to require a particular orientation. Terms relating to attachment, coupling, etc. (e.g., “connected” and “attached”) refer to a relationship, as well as a movable or rigid attachment or relationship in which these structures are directly or indirectly fixed or attached to each other through an intermediate structure, unless otherwise explicitly stated.

As shown in FIG. 1, an automatic sandpaper replacement device for CNC production line, comprises:

an automatic sandpaper supply mechanism 1, and an automatic sandpaper peeling mechanism 2, wherein the automatic sandpaper supply mechanism 1 comprises a bracket assembly 11, and a sandpaper receiving assembly 13 and a sandpaper extracting plate 113 disposed on the bracket assembly 11. The automatic sandpaper peeling mechanism 2 is mated with the bracket assembly 11, and the automatic sandpaper peeling mechanism 2 comprises a mounting plate 21, and a peeling drive assembly 22 and a peeling assembly 23 mounted on the mounting plate 21. The peeling assembly 23 is drivingly connected with the peeling drive assembly 22, the peeling assembly 23 periodically peels off waste sandpaper on a sanding head under driving of the peeling drive assembly 22, and the sandpaper extracting plate 113 periodically supplies new sandpaper to the sanding head after peeling off the sandpaper. By employing this structural design, peeling and replacement of the sandpaper can be completed in a single operation, thereby omitting intermediate steps, improving peeling and replacement efficiency of the sandpaper, and further improving production efficiency.

As shown in FIG. 2 and FIG. 3, the automatic sandpaper supply mechanism 1 comprises a bracket assembly 11, and a sandpaper receiving assembly 13, wherein the bracket assembly 11 comprises a base plate 112 and a sandpaper extracting driving part 115, and the sandpaper receiving assembly 13 is disposed on the base plate 112. In addition, a sandpaper extracting plate 113 is also disposed on the base plate 112. The sandpaper receiving assembly 13 comprises a sandpaper receiving canister 131 and a sandpaper pressing block 132. The sandpaper extracting plate 113 is slidably connected to the base plate 112, and the sandpaper receiving canister 131 is provided with a first through hole 134 running through the upper and lower ends of the sandpaper receiving canister so that the upper end and the lower end of the sandpaper receiving canister 131 are both open. The bottom of the sandpaper receiving canister 131 is provided with a second through hole 135 running through the left and right sides of the sandpaper receiving canister so that the bottom of the sandpaper receiving canister 131 is provided with a left through opening and a right through opening, the sandpaper pressing block 132 is slidably disposed in the first through hole 134, the sandpaper extracting plate 113 is passed through the second through hole 135, and the sandpaper extracting plate 113 can be reciprocally slide along the base plate 112 under driving of the sandpaper extracting driving part 115. The through direction of the second through hole 135 is same as the slip direction of the sandpaper extracting plate 113. Generally, an sandpaper group placed in a stacked manner can be placed in the sandpaper receiving canister 131. Since the edge of the sandpaper is somewhat warped, the sandpaper pressing block 132 can not only press and flat the sandpaper, but also provide a vertical downward propulsive force to the sandpaper group, so that the remaining sandpaper can travel down a certain distance under the action of its own gravity and propulsive force when sandpaper at the very bottom is taken out, so as to be ready for the next sandpaper extracting. In this way, the sandpaper extracting plate can periodically and uninterruptedly take out the sandpaper from the sandpaper receiving canister. In an embodiment, a pressing block handle 1321 is connected to the top of the sandpaper pressing block 132. In a preferred embodiment, several observation windows are provided on the side wall of the sandpaper receiving canister 131 for observing the residual amount of sandpaper in the sandpaper receiving canister 131.

As shown in FIG. 2, FIG. 3 and FIG. 10, a sandpaper guiding plate 133 is disposed in the second through hole 135, and above the sandpaper extracting plate 113. The sandpaper guiding plate 133 is provided with a sandpaper guiding through hole 1331. The aperture size of the sandpaper guiding through hole 1331 is the same as that of the first through hole 134. The sandpaper guiding through hole 1331 is provided concentrically with the first through hole 134, so that sandpaper in the sandpaper receiving canister 131 can be smoothly guided to the sandpaper extracting plate 113 after being guided by the sandpaper guiding plate 133.

Further, a sandpaper extracting groove 1131 is provided on an upper surface of the sandpaper extracting plate 113. The sandpaper extracting groove 1131 is located at one end of the sandpaper extracting plate 113. The sandpaper extracting groove 1131 is selectively mated with the first through hole 134 in the process of reciprocally sliding of the sandpaper extracting plate 113 along the base plate 112.

As shown in FIG. 2-FIG. 6, a sandpaper division member 14 is disposed on the base plate 112 and on the side of the sandpaper receiving assembly 13. The sandpaper division member 14 comprises:

a division bracket;

a division driver 143 disposed on the division bracket; and

a division plate 145 disposed on the division bracket,

wherein the division plate 145 can be selectively inserted between the sandpaper guiding plate 133 and the sandpaper extracting plate 113 under driving of the division driver 143. In this way, when sandpaper is introduced into the sandpaper extracting groove 1131, the division plate 145 can divide the sandpaper in the sandpaper extracting groove 1131 with the remaining sandpaper above it to prevent the sandpaper in the sandpaper extracting groove 1131 from sticking to the remaining sandpaper, and when sandpaper is to be introduced into the sandpaper extracting groove 1131, the division plate can be removed from between the sandpaper guiding plate 133 and the sandpaper extracting plate 113, so that the sandpaper can be smoothly introduced into the sandpaper extracting groove 1131. In an embodiment, the division bracket comprises a left bracket 141 and a right bracket 142. The left bracket 141 is parallel with and spaced apart from the right bracket 142. At least two guide posts 144 are disposed between the left bracket 141 and the right bracket 142, and the division driver 143 is slidably sleeved on the guide post 144. In a preferred embodiment, the division bracket and the division driver 143 are capped with a protective cover 146 which provides an entry and exit passageway for the division plate 145.

Further, a sandpaper extracting guide rail 114 is disposed on the base plate 112, and the sandpaper extracting plate 113 is slidably coupled to the sandpaper extracting guide rail 114.

Further, the sandpaper division member 14 is mounted over the sandpaper extracting guide rail 114, and the division plate 145 is spaced apart from the sandpaper extracting guide rail 114, thereby saving space and reducing the floor area of the equipment.

As shown in FIG. 6-FIG. 9, a sandpaper attaching workstation P1 and a sandpaper division workstation P2 are disposed on the sandpaper extracting guide rail 114 in this order along an extending direction of the sandpaper extracting guide rail. During the sliding process with the sandpaper extracting plate 113, the sandpaper extracting groove 1131 alternately moves from the sandpaper attaching workstation P1 to the sandpaper division workstation P2 or moves from the sandpaper division workstation P2 to the sandpaper attaching workstation P1. Thereby, after the sandpaper at the sandpaper division workstation P2 is taken out by the sandpaper extracting groove 1131, the sandpaper extracting groove 1131 moves to the sandpaper attaching workstation P1 to wait for the sanding head to take out the sandpaper from the sandpaper attaching workstation P1.

Further, the depth of the sandpaper extracting groove 1131 is greater than the thickness of single piece of sandpaper and less than the thickness of two pieces of sandpaper. Since the edge of the sandpaper is somewhat warped, the division plate 145 can conveniently separate the sandpaper in the sandpaper extracting groove 1131 from other sandpaper, thereby further ensuring the success rate of taking out only one piece of sandpaper in a single time.

As shown in FIG. 9, the sandpaper extracting driving part 115 comprises:

a guiding rod 1152 disposed on the base plate 112, an extending direction of which being same as an extending direction of the sandpaper extracting guide rail 114; and

a first driver 1151 slidably sleeved on the guiding rod 1152,

wherein the first driver 1151 is drivingly connected to the sandpaper extracting plate 113. In a preferred embodiment, the sandpaper extracting driving part 115 is capped with a protective plate of driving part 111.

As shown in FIG. 3, FIG. 4 and FIG. 6, a through hole running through the sandpaper extracting plate 113 is provided at the bottom of the sandpaper extracting groove 1131. A sandpaper detecting sensor 116 for sensing whether there is sandpaper in the sandpaper extracting groove 1131 is provided below the base plate 112 and at the sandpaper attaching workstation P1. A position sensor 1121 is provided above the base plate 112 and at the sandpaper attaching workstation P1, and the position sensor 1121 is located beside the sandpaper extracting plate 113.

As shown in FIG. 2 and FIG. 3, the base plate 112 is further provided with a positioning assembly of sanding head 12, and the positioning assembly of sanding head 12 comprises:

a positioning bottom plate 121 disposed on the base plate 112; and

a first positioning block 122, a second positioning block 123, and a third positioning block 124 that are disposed at the edge of the positioning bottom plate 121,

wherein the first positioning block 122, the second positioning block 123, and the third positioning block 124 surround to form a first positioning channel 125 between the first positioning block 122 and the second positioning block 123, and a second positioning channel 126 between the second positioning block 123 and the third positioning block 124. The first positioning channel 125 and the second positioning channel 126 are interconnected and are perpendicular to each other. Since the sanding head and its driver are eccentric connected, after being positioned through the first positioning channel 125 and the second positioning channel 126, the sanding head can accurately attach the sandpaper onto it at the sandpaper attaching workstation P1.

As shown in FIG. 12, a sanding machine tool is usually equipped with a sanding head 3, and the sanding head 3 is connected with replaceable sandpaper. In practical applications, the inventors have found that the connection method between the sandpaper and the sanding head 3 in the prior art cannot meet the practical application requirements, and there is often a phenomenon that the sandpaper is detached or undergoing locally increased wear in the sanding process. In view of this, the inventors propose a sandpaper attachment structure 31 disposed between the sanding head 3 and the sandpaper. As shown in FIG. 16, the sandpaper attachment structure 31 comprises a cushion 312, and sandpaper 311 attached to one of the sides of the cushion 312. The other side of the cushion 312 is attached to the sanding head 3. In this case, the attachments among the cushion 312, the sanding head 3 and the sandpaper 311 are achieved by magic stickers. Since sticking effect of the magic sticker is strong after changing the sandpaper attachment structure, in the practical applications, there is new problems that the sandpaper 311 is not easily peeled off from the cushion 312 and residues after peeling off. In view of this, the inventors propose an automatic sandpaper peeling mechanism 2 for CNC production line to solve the above problems.

As shown in FIG. 1 and FIG. 11, the automatic sandpaper peeling mechanism 2 comprises a mounting plate 21, a peeling drive assembly 22 and a peeling assembly 23, wherein the mounting plate 21 extends in a vertical direction, the peeling drive assembly 22 is mounted on the mounting plate 21, and the peeling assembly 23 is drivingly connected with the peeling drive assembly 22. The peeling assembly 23 comprises a peeling mounting plate 231 and a peeling plate 232 fixedly mounted on the peeling mounting plate 231. The peeling mounting plate 231 extends in a vertical direction, the peeling mounting plate 231 is drivingly connected with the peeling drive assembly 22, and the peeling mounting plate 231 can be reciprocated in a vertical plane under the driving of the peeling drive assembly 22. In an embodiment, the peeling drive assembly 22 comprises a peeling drive cylinder 221 and a connecting block 222 fixed to the power output end of the peeling drive cylinder 221. The peeling drive cylinder 221 drives the connecting block 222 to reciprocate in a vertical plane, and the connecting block 222 is fixed to the top of the peeling mounting plate 231 so that the peeling mounting plate 231 is parallel with and spaced apart from the mounting plate 21, thereby forming a sandpaper falling channel between the peeling mounting plate 231 and the mounting plate 21. In this way, the peeled waste sandpaper can freely fall through the sandpaper falling channel to facilitate subsequent collection of waste sandpaper. In a preferred embodiment, the mounting plate 21 is provided with a left limiting block 211 and a right limiting block 212, and the left limiting block 211 and the right limiting block 212 are located at the highest position of the peeling mounting plate 231. A protective cover of peeling mechanism 25 is usually capped on the peeling assembly 23 and the peeling drive assembly 22.

Turning to FIG. 11 again, a fitting plate 233 is fixedly mounted on the peeling mounting plate 231, and the fitting plate 233 is located directly below the peeling plate 232. Since the sandpaper may be somewhat warped and damaged after sanding and the fitting plate 233 can apply a certain pressure to the sandpaper, the sandpaper is pressed and flattened so that the peeling plate 232 can easily and quickly invade the sandpaper layer, thereby improving success rate for peeling off the sandpaper.

Further, the peeling plate 232 and the fitting plate 233 are located in the same vertical plane and are spaced apart to form a sandpaper collecting space between them. In a preferred embodiment, the peeling mounting plate 231 has an inverted U-shaped structure, and the peeling mounting plate 231 comprises a top plate fixed to the connecting block 222 and a left cantilever and a right cantilever respectively fixed to the two ends of the top plate. The left cantilever and the right cantilever are parallel to each other and spaced apart from each other to form a retaining space between them. The peeling plate 232 and the fitting plate 233 are both mounted between the left cantilever and the right cantilever. The peeled waste sandpaper can be timely and effectively guided into the sandpaper falling channel between the peeling mounting plate 231 and the mounting plate 21 by the sandpaper collecting space to facilitate discharging it in time, to prevent the waste sandpaper from interfering with subsequent peeling actions.

Further, a distance between the peeling plate 232 and the fitting plate 233 is 8 mm to 15 mm. In an embodiment, the distance between the peeling plate 232 and the fitting plate 233 is 8 mm. In another embodiment, the distance between the peeling plate 232 and the fitting plate 233 is 10 mm. In still another embodiment, the distance between the peeling plate 232 and the fitting plate 233 is 15 mm.

As shown in enlarged partial diagrams of FIG. 13 and FIG. 14, a lower edge of the peeling plate 232 is provided with a peeling guide slope 2321 extending obliquely upward along the inner side of the peeling plate 232, and an angle θ between the peeling guide slope 2321 and the vertical plane is as follows: 3°≤θ≤8°. The peeling guide slope 2321 enables peeled waste sandpaper to be guided obliquely upward into the sandpaper falling channel between the peeling mounting plate 231 and the mounting plate 21, improving discharge efficiency of the waste sandpaper. In an embodiment, θ=5°. In a preferred embodiment, the sandpaper falling channel is further provided with a sandpaper scraper 235 fixed to the inner side of the peeling mounting plate 231, and the end of the sandpaper scraper 235 abuts against the side wall of the mounting plate 21. In this way, in a process of peeling off sandpaper, the sandpaper scraper 235 can downward scrape the peeled waste sandpaper in time to prevent the waste sandpaper from being excessive and clogging the sandpaper falling channel.

Further, a sandpaper guiding structure having a mountain-shaped cross section is integrally formed at an upper edge of the fitting plate 233, and the sandpaper guiding structure comprises:

a first guiding slope 2331 extending obliquely upward on the outer side of the fitting plate 233, the first guiding slope 2331 being inclined to the inner side of the fitting plate 233; and

a second guiding slope 2332 extending obliquely upward on the inner side of the fitting plate 233, the second guiding slope 2332 being inclined to the outer side of the fitting plate 233;

wherein an angle α between the first guiding slope 2331 and the vertical plane and an angle β between the second guiding slope 2332 and the vertical plane are as follows: 15°≤α≤30°, 5°≤β≤15°. On the one hand, the sandpaper guiding structure can prevent the peeling plate 232 from being difficult to invade due to the over-tightening of the upper edge of the sandpaper by the fitting plate 233. And on the other hand, the sandpaper guiding structure can prevent the waste sandpaper debris from remaining on the top of the fitting plate 233, thereby facilitating the effective discharge of the waste sandpaper.

As shown in FIG. 11-FIG. 15, several peeling teeth 234 are provided at the lower edge of the peeling plate 232.

Further, the peeling teeth 234 extend in the vertical direction, and the adjacent peeling tooth 234 are parallel to and spaced apart from each other. The plurality of peeling teeth 234 can be formed into a claw-shaped structure by employing such a structure in order to invade the sandpaper layer more quickly and smoothly, thereby improving peeling efficiency of the sandpaper.

As shown in FIG. 11, a bracket 213 is fixedly mounted on the peeling mounting plate 231. The bracket 213 is provided with a positioning plate of sanding head 214. The positioning plate of sanding head 214 is provided with at least one receiving groove of sanding head 2141, and a peeling channel is formed between the bracket 213 and the peeling mounting plate 231 to allow the peeling mounting plate 231 and the peeling plate 232 to pass through.

Further, a waste sandpaper storage box 24 having a certain receiving space is connected directly below the mounting plate 21, and the waste sandpaper storage box 24 is open at the top thereof. The waste sandpaper storage box 24 is located directly below the peeling channel. As shown in FIG. 5, the peeled waste sandpaper can be directly dropped into the waste sandpaper storage box 24 through the top opening of the waste sandpaper storage box 24. In this way, the peeled waste sandpaper can be collected quickly and effectively, and it will not pollute a production workshop and machine table, so this embodiment has relatively high practical value.

The work principle of the embodiment disclosed by the present disclosure is as follows: first, the sandpaper extracting plate 113 and the division plate 145 are in the state shown in FIG. 6 to FIG. 8. At this time, the sandpaper extracting groove 1131 is located at the sandpaper division workstation P2. When a piece of sandpaper is dropped from the sandpaper receiving canister 131 into the sandpaper extracting groove 1131, the division plate 145 is inserted between the sandpaper guiding plate 133 and the sandpaper extracting plate 113, so that the sandpaper in the sandpaper extracting groove 1131 is separated from other sandpaper and the remaining sandpaper is no longer dropped. The sandpaper extracting plate 113 moves toward the sandpaper attaching workstation P1 until the sandpaper extracting groove 1131 moves to the sandpaper attaching workstation P1. Waste sandpaper on the sanding head after sanding is peeled off by the automatic sandpaper peeling mechanism 2, and then the sanding head is positioned through the positioning assembly of sanding head 12. The sanding head is clamped to the sandpaper attaching workstation P1 by a robot hand and the sandpaper on the sandpaper extracting groove 1131 is attached onto the sanding head. At the sandpaper division workstation P2, the division plate 145 causes the sandpaper in the sandpaper receiving canister 131 to no longer drop until the sandpaper extracting groove 1131 returns to the sandpaper attaching workstation P1 again. The reciprocation cycle continues until the sandpaper in the sandpaper receiving canister 131 is completely taken out. When the sandpaper in the sandpaper receiving canister 131 is completely taken out, a next group of sandpaper can be loaded into the sandpaper receiving canister 131 as required.

The number of devices and processing scales described herein are intended to simplify the description of the present invention. Applicability, modifications, and variations of the present invention will be apparent to the person skilled in the art.

Although embodiments of the present invention have been disclosed as above, they are not limited to the implementations listed in the specification and embodiments. They can be applied to all kinds of fields suitable for the present invention. Additional modifications can be easily implemented to those who are familiar with the field. Therefore, the present invention is not limited to specific details and the legends shown and described herein without deviation from the general concepts defined in the claims and the equivalents. 

What is claimed is:
 1. An automatic sandpaper replacement device for CNC production line, being characterized in that it comprises: an automatic sandpaper supply mechanism, the automatic sandpaper supply mechanism comprising a bracket assembly, and a sandpaper receiving assembly and a sandpaper extracting plate disposed on the bracket assembly; and an automatic sandpaper peeling mechanism that is mated with the bracket assembly, the automatic sandpaper peeling mechanism comprising a mounting plate, and a peeling drive assembly and a peeling assembly mounted on the mounting plate; wherein the peeling assembly is drivingly connected with the peeling drive assembly, the peeling assembly periodically peels off waste sandpaper on a sanding head under driving of the peeling drive assembly, and the sandpaper extracting plate periodically supplies new sandpaper to the sanding head after peeling off sandpaper.
 2. The automatic sandpaper replacement device for CNC production line according to claim 1, being characterized in that, the bracket assembly comprises a base plate and a sandpaper extracting driving part, and the sandpaper receiving assembly and the sandpaper extracting plate are disposed on the base plate.
 3. The automatic sandpaper replacement device for CNC production line according to claim 2, being characterized in that, the sandpaper receiving assembly comprises a sandpaper receiving canister and a sandpaper pressing block, the sandpaper extracting plate is slidably connected to the base plate, and the sandpaper receiving canister is provided with a first through hole running through the upper and lower ends of the sandpaper receiving canister so that the upper end and the lower end of the sandpaper receiving canister are both open.
 4. The automatic sandpaper replacement device for CNC production line according to claim 2, being characterized in that, the bottom of the sandpaper receiving canister is provided with a second through hole running through the left and right sides of the sandpaper receiving canister so that the bottom of the sandpaper receiving canister is provided with a left through opening and a right through opening, the sandpaper pressing block is slidably disposed in the first through hole, the sandpaper extracting plate is passed through the second through hole, and the sandpaper extracting plate can be reciprocally slide along the base plate under driving of the sandpaper extracting driving part.
 5. The automatic sandpaper replacement device for CNC production line according to claim 1, being characterized in that, the mounting plate is mated with the bracket assembly and extends in a vertical direction, and the peeling assembly comprises a peeling mounting plate and a peeling plate fixedly mounted on the peeling mounting plate, wherein the peeling mounting plate extends in a vertical direction, the peeling mounting plate is drivingly connected to the peeling drive assembly, and the peeling plate can be reciprocated in a vertical plane with the peeling mounting plate under driving of the peeling drive assembly.
 6. The automatic sandpaper replacement device for CNC production line according to claim 5, being characterized in that, a fitting plate is fixedly mounted on the peeling mounting plate, and the fitting plate is located directly below the peeling plate.
 7. The automatic sandpaper replacement device for CNC production line according to claim 6, being characterized in that, the peeling plate and the fitting plate are located in the same vertical plane, and are spaced apart to form a sandpaper collecting space between them.
 8. The automatic sandpaper replacement device for CNC production line according to claim 6, being characterized in that, a lower edge of the peeling plate is provided with a peeling guide slope extending obliquely upward along the inner side of the peeling plate, and an angle θ between the peeling guide slope and the vertical plane is as follows: 3°≤θ≤8°.
 9. The automatic sandpaper replacement device for CNC production line according to claim 6, being characterized in that, a sandpaper guiding structure having a mountain-shaped cross section is integrally formed at an upper edge of the fitting plate, and the sandpaper guiding structure comprises: a first guiding slope extending obliquely upward on the outer side of the fitting plate, the first guiding slope being inclined to the inner side of the fitting plate; and a second guiding slope extending obliquely upward on the inner side of the fitting plate, the second guiding slope being inclined to the outer side of the fitting plate; wherein an angle α between the first guiding slope and the vertical plane and an angle β between the second guiding slope and the vertical plane are as follows: 15°≤α≤30°, 5°≤β≤15°.
 10. The automatic sandpaper replacement device for CNC production line according to claim 2, being characterized in that, a sandpaper extracting groove is disposed on an upper surface of the sandpaper extracting plate, the sandpaper extracting groove is located at one end of the sandpaper extracting plate, and the sandpaper extracting groove is selectively mated with the first through hole in the process of reciprocally sliding of the sandpaper extracting plate along the base plate. 